Resin composition, adhesives prepared therewith for bonding circuit members, and circuit boards

ABSTRACT

The present invention relates to a resin composition which gives a resin product with a low hygroscopic property, an adhesive for connecting a circuit member and a circuit board, and provides a resin composition, an adhesive for connecting a circuit member and a circuit board comprising (A) a polyhydroxy polyether resin represented by the 
                 
 
formula (I):
         wherein R 1  to R 8  each represent H, C 1-4  alkyl group, C 2-5  alkenyl group, C 1-4  hydroxyalkyl group or halogen atom; R a  represents H or C 1-2  alkyl group; R b  represents C 2-13  alkyl group; and n is a recurring number, or the following formula (II):   wherein R 9  to R 12  each represent H, C 1-6  alkyl group, C 1-6  hydroxyalkyl group or halogen atom; R c  to R f  each represent H, C 1-6  alkyl group, cyclohexyl group, aryl group, aralkyl group or halogen atom; and m is a recurring number,
 
and (B) a three dimensionally cross-linkable resin.

FIELD OF THE INVENTION

The present invention relates to a resin composition, and an adhesivefor connecting a circuit member and a circuit board using the same, morespecifically, to a resin composition providing a low hygroscopic resinmolded product, in particular, a resin composition suitable for acircuit connecting member for electronic parts, an adhesive forconnecting a circuit member to be used for connecting circuit boards oran IC chip or electronic parts and a circuit board, and a circuit boardin which a semiconductor chip is adhered and fixed to a substrate by anadhesive according to, for example, the flip chip application system,and both electrodes are electrically connected.

PRIOR ART

At present, an organic material such as an epoxy resin, etc. has beenwidely used in the field of a semiconductor. In the field of anencapsulating material, 90% of an encapsulating system is replaced witha resin encapsulation system. The encapsulating material is a compositematerial constituted by an epoxy resin, a curing agent, various kinds ofadditives, an inorganic filler, etc., and as the epoxy resin, acresol-novolak type epoxy resin has widely been used. However, thecresol-novolak type epoxy resin does not have required characteristicssuch as low water-absorption property, low elasticity, etc., so that itis difficult to apply to a surface application system. Thus, a number ofnovel and high performance epoxy resins have been proposed andpractically used in place of the above.

Also, as a conductive adhesive agent for die bonding, a silver paste inwhich silver powder is kneaded in an epoxy resin has widely been used.However, accompanying with change in a mounting system of semiconductorelements on a wiring board to the surface application system, it hasbeen earnestly desired to improve solder resistance reflow property ofthe silver paste. To solve this problem, improvements in voids, peelstrength, water absorption rate, elasticity, etc., of an adhesive layerfor die bonding after curing have been made.

In the field of a semiconductor application, as a novel applicationsystem corresponding to low cost and high resolution, a flip chipapplication in which an IC chip is directly mounted on a printing boardor a flexible wiring board has been attracting attention. As the flipchip application system, there has been known a system in which solderbump is provided at a terminal of the chip, and solder connection iscarried out, or a system in which electronic connection is carried outthrough a conductive adhesive. In these systems, there is a problem thata stress based on the difference in thermal expansion coefficients ofthe chip and the substrate to be connected occurs at the connectioninterface when it is exposed to various kinds of environments andconnection reliability is lowered. Thus, to relax the stress at theconnection interface, it has been studied to use a system in which anepoxy resin type under fill material is injected into a gap between thechip/substrate. This under fill injecting step, however, makes theprocess complicated and there are problems of causing disadvantages inproductivity and costs. To solve such problems, in recent years, a flipchip application using an anisotropic conductive adhesive havinganisotropic conductivity and encapsulating function has been attractedattention in the viewpoint of simple and easy processability.

When the chip is mounted on a substrate through an anisotropicconductive material, under hygroscopic conditions, an adhesive forcebetween the adhesive and the chip or between the adhesive and theinterface of the substrate is lowered. Moreover, under temperature cycleconditions, a stress based on the difference in thermal expansioncoefficients of the chip and the substrate occurs at the connectionportion whereby there are problems of increase in connection resistanceor peeling of the adhesive when reliability tests such as a thermalimpact resistance test, a PCT (pressure cooker test) test, a hightemperature and high humidity test, etc. are carried out. Also, in asemiconductor package, a solder resistant reflow temperature test iscarried out after absorbing water by a high temperature and highhumidity test, there are problems that a connection resistance isincreased or peeling of the adhesive occurs due to abrupt expansion ofwater component absorbed in the adhesive. In general, for the purpose ofrelaxing internal stress of an epoxy resin and for strengthening theresin, a technique in which a liquid rubber or cross-linked rubber, andcore-shell type rubber particles are dispersed has been known. However,in a cured product in which a rubber is dispersed in an epoxy resin, ithas been known that a softening point temperature (or a glass transitiontemperature, hereinafter referred to as Tg) is lowered as compared tothat of the cured product comprising the epoxy resin alone so that itbecomes a cause of lowering in reliability in the field of requiringhigh heat resistance. On the other hand, when a cross linking density ofthe epoxy resin is increased to improve Tg in a rubber dispersionsystem, it causes lowering in an effect of rubber dispersion andincreasing in brittleness of the cured product as well as increasingwater absorption ratio whereby it becomes a cause of loweringreliability. Also, as a method of strengthening an epoxy resin withoutlowering Tg, a formulation with a high heat resistant thermoplasticresin which has been known as an engineering plastic has been known.However, these engineering plastics are generally poor in solubility ina solvent so that a formulation with an epoxy resin is prepared bykneading of powder whereby a development of the material to the use ofan adhesive is not suitable.

An object of the present invention is to provide a resin compositionproviding a low hygroscopic resin molded product, in particular, a resincomposition which is suitable when it is used as an adhesive or acircuit connecting member for electronic parts, as well as to provide anadhesive for connecting a circuit member and a circuit board whereinthere is no increase in connecting resistance at the connected portionor no peeling of the adhesive, and connecting reliance is markedlyimproved.

DISCLOSURE OF THE INVENTION

The present invention relates to a resin composition which comprises (A)a polyhydroxy polyether resin represented by the following formula (I):

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ may be the same or differentfrom each other and each represent a hydrogen atom, a straight orbranched alkyl group having 1 to 4 carbon atoms, an alkenyl group having2 to 5 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms ora halogen atom; R_(a) represents a hydrogen atom or an alkyl grouphaving 1 to 2 carbon atoms; R_(b) represents a straight or branchedalkyl group having 2 to 13 carbon atoms; and n is a number of arecurring unit and satisfying that a weight average molecular weight ofthe polyhydroxy polyether resin in terms of standard polystyrene is5,000 to 1,000,000,and (B) a three dimensionally cross-linkable resin.

The present invention also relates to an adhesive for connecting acircuit member, which interposes between circuit electrodes opposed toeach other, and, when these circuit electrodes opposed to each other arepressed, electrically connects these electrodes in a pressed direction,and comprises (A) a polyhydroxy polyether resin represented by theabove-mentioned formula (I) and/or the following formula (II):

wherein R⁹, R¹⁰, R¹¹ and R¹² may be the same or different from eachother and each represent a hydrogen atom, a straight or branched alkylgroup having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6carbon atoms or a halogen atom; R_(c), R_(d), R_(e) and R_(f) may be thesame or different from each other and each represent a hydrogen atom, astraight or branched alkyl group having 1 to 6 carbon atoms, acycloalkyl group having 6 carbon atoms, an aryl group, an aralkyl groupor a halogen atom; and m is a number of a recurring unit and satisfyingthat a weight average molecular weight of the polyhydroxy polyetherresin in terms of standard polystyrene is 5,000 to 1,000,000,and (B) a three dimensionally cross-linkable resin.

Moreover, the present invention relates to a circuit board whichcomprises a first circuit member having a first connecting terminal anda second circuit memberhaving a second connecting terminal which are soprovided to oppose to each other, and an adhesive interposed between thefirst connecting terminal and the second connecting terminal opposed toeach other, and the first connecting terminal and the second connectingterminal opposed to each other being electrically connected by heatingand pressurizing, wherein said adhesive contains (A) the polyhydroxypolyether resin represented by the above-mentioned formula (I) and/or(II), and (B) a three dimensionally cross-linkable resin.

BEST MODE FOR CARRYING OUT THE INVENTION

The resin composition of the present invention is preferably used as amember for connecting a circuit member. It is preferably used as aconnecting member for a flip chip application or for an adhesive foradhering a circuit member which connects the first circuit member havingthe first connecting terminal and the second circuit member having thesecond connecting terminal.

As the circuit member to be used in the present invention, there may bementioned chip parts such as a semiconductor chip, a resister chip, acondenser chip, etc.; and a substrate such as a printing board, aflexible wiring board which uses polyimide or polyester as a basematerial, an ITO glass substrate, etc. On a semiconductor chip or anelectrode pad of a substrate, a gold ball is formed by melting a bumpformed by plating or a tip of a gold wire with a torch, etc., and afterpress-contacting the ball on the electrode pad, a projected electrodesuch as a wire bump obtained by cutting a wire is provided whereby it isused as a connection terminal.

In the adhesive for connecting a circuit member of the presentinvention, a polyhydroxy polyether resin represented by theabove-mentioned formula (I) and/or (II) is used. It is preferred thatwater absorption rate of the resin represented by the formula (I) is 0.1to 1.2% by weight and a glass transition temperature thereof is 40 to100° C. Also, the polyhydroxy polyether resin represented by the formula(II) preferably has a glass transition temperature of 60 to 120° C.Moreover, the polyhydroxy polyether resin represented by the formula (I)and/or (II) is preferably soluble in a mixed solvent of an aromatichydrocarbon solvent and an oxygen atom-containing organic solvent.

The polyhydroxy polyether resin represented by the formula (I) can besynthesized by a biphenol compound and a bisphenol compound or theirdiglycidyl compounds.

In the formula (I), R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are as mentionedabove, may be the same or different from each other and each represent ahydrogen atom, a straight or branched alkyl group having 1 to 4 carbonatoms, an alkenyl group having 2 to 5 carbon atoms, a hydroxyalkyl grouphaving 1 to 4 carbon atoms or a halogen atom. As the straight orbranched alkyl group having 1 to 4 carbon atoms, there may be mentioneda methyl group, an ethyl group, an n-propyl group, an isopropyl group,an n-butyl group, an isobutyl group and a sec-butyl group, preferably amethyl group, an ethyl group, an n-propyl group and an n-butyl group. Asthe alkenyl group having 2 to 5 carbon atoms, there may be mentioned anethynyl group, a propenyl group, a butenyl group, etc., and preferably apropenyl group. As the hydroxyalkyl group having 1 to 4 carbon atoms,there may be mentioned a hydroxymethyl group, a hydroxyethyl group, ahydroxypropyl group and a hydroxy-butyl group, and preferably ahydroxymethyl group. As the halogen atom, there may be mentioned afluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.,and preferably a fluorine atom. Of these, a hydrogen atom, a methylgroup, a hydroxymethyl group and a fluorine atom are particularlypreferred. R_(a) represents a hydrogen atom or an alkyl group having 1to 2 carbon atoms, preferably a hydrogen atom or a methyl group, andparticularly preferably a methyl group. R_(b) represents a straight orbranched alkyl group having 2 to 13 carbon atoms, and there may bementioned, for example, an ethyl group, an n-propyl group, an isopropylgroup, an n-butyl group, an isobutyl group and a sec-butyl group,preferably a methyl group, an ethyl group, an n-propyl group, an n-butylgroup, an n-pentyl group, an n-hexyl group, an n-heptyl group, ann-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group,an n-dodecyl group and an n-tridecyl group, etc., preferably a straightalkyl group having 6 to 9 carbon atoms. n is a number of a recurringunit and satisfying that a weight average molecular weight of thepolyhydroxy polyether resin in terms of standard polystyrene is 5,000 to1,000,000.

As the biphenol compound for synthesizing the polyhydroxy polyetherresin, there may be mentioned, for example, 1,1′-biphenyl-4,4′-diol(wherein R¹, R², R³ and R⁴ are all hydrogen atoms),3,3′-dimethyl-(1,1′-biphenyl)-4,4′-diol (R¹ and R³ are alkyl groupshaving 1 carbon atom, and R² and R⁴ are hydrogen atoms),3,3′,5,5′-tetramethyl-(1,1′-biphenyl)-4,4′-diol (wherein R¹, R², R³ andR⁴ are all alkyl groups having 1 carbon atom),3,3′-bis(2-propenyl)-(1,1′-biphenyl)-4,4′-diol (R¹ and R³ are alkenylgroups having 3 carbon atom, and R² and R⁴ are hydrogen atoms),2,2′-dibutyl-5,5′-dimethyl-(1,1′-biphenyl)-4,4′-diol (R¹ and R³ arealkyl groups having 1 carbon atom, and R² and R⁴ are alkyl groups having4 carbon atoms),3,3′,5,5′-tetrakis(hydroxymethyl)-(1,1′-biphenyl)-4,4-diol (wherein R¹,R², R³ and R⁴ are all hydroxymethyl groups),3,3′-difluoro-(1,1′-biphenyl)-4,4′-diol (R¹ and R³ are fluorine atoms,and R² and R⁴ are hydrogen atoms), and3,3′,5,5′-tetrafluoro-(1,1′-biphenyl)-4,4′-diol (wherein R¹, R², R³ andR⁴ are all fluorine atoms).

As the bisphenol compound, there may be mentioned, for example,1,1-(4,4′-dihydroxydiphenyl)-3-methylbutane (R_(a) is a hydrogen atom,and R_(b) is a branched alkyl group having 4 carbon atoms),2,2-(4,4′-dihyroxydiphenyl)-4-methylpentane (R_(a) is an alkyl grouphaving 1 carbon atom, and R_(b) is a branched alkyl group having 4carbon atoms), 1,1-(4,4′-dihydroxydiphenyl)-3-ethylhexane (R_(a) is ahydrogen atom, and R_(b) is a branched alkyl group having 7 carbonatoms), 3,3-(4,4′-dihyroxydiphenyl)pentane (R_(a) is an alkyl grouphaving 2 carbon atoms, and R_(b) is an alkyl group having 2 carbonatoms), 2,2-(4,4′-dihyroxydiphenyl)-heptane (R_(a) is an alkyl grouphaving 1 carbon atom, and R_(b) is a straight alkyl group having 5carbon atoms), 1,1-(4,4′-dihydroxydiphenyl)heptane (R_(a) is a hydrogenatom, and R_(b) is a straight alkyl group having 6 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)octane (R_(a) is an alkyl group having 1carbon atom, and R_(b) is a straight alkyl group having 6 carbon atoms),1,1-(4,4′-dihydroxydiphenyl)octane (R_(a) is a hydrogen atom, and R_(b)is a straight alkyl group having 7 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)nonane (R_(a) is an alkyl group having 1carbon atom, and R_(b) is a straight alkyl group having 7 carbon atoms),1,1-(4,4′-dihydroxydiphenyl)nonane (R_(a) is a hydrogen atom, and R_(b)is a straight alkyl group having 8 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)decane (R_(a) is an alkyl group having 1carbon atom, and R_(b) is a straight alkyl group having 8 carbon atoms),1,1-(4,4′-dihydroxydiphenyl)decane (R_(a) is a hydrogen atom, and R_(b)is a straight alkyl group having 9 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)undecane (R_(a) is an alkyl group having 1carbon atom, and R_(b) is a straight alkyl group having 9 carbon atoms),1,1-(4,4′-dihydroxy-diphenyl)undecane (R_(a) is a hydrogen atom, andR_(b) is a straight alkyl group having 10 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)dodecane (R_(a) is an alkyl group having 1carbon atom, and R_(b) is a straight alkyl group having 10 carbonatoms), 1,1-(4,4′-dihydroxydiphenyl)dodecane (R_(a) is a hydrogen atom,and R_(b) is a straight alkyl group having 11 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)tridecane (R_(a) is an alkyl group having 1carbon atom, and R_(b) is a straight alkyl group having 11 carbonatoms), 1,1-(4,4′-dihydroxydiphenyl)tridecane (R_(a) is a hydrogen atom,and R_(b) is a straight alkyl group having 12 carbon atoms),2,2-(4,4′-dihydroxydiphenyl)tetradecane (R_(a) is an alkyl group having1 carbon atom, and R_(b) is a straight alkyl group having 12 carbonatoms), 1,1-(4,4′-dihydroxydiphenyl)-tetradecane (R_(a) is a hydrogenatom, and R_(b) is a straight alkyl group having 13 carbon atoms) and2,2-(4,4′-dihydroxydiphenyl)pentadecane (R_(a) is an alkyl group having1 carbon atom, and R_(b) is a straight alkyl group having 13 carbonatoms), and these may be used in combination of two or more by mixing.Of these, 2,2-(4,4′-dihyroxydiphenyl)-octane (R_(a) is an alkyl grouphaving 1 carbon atom, and R_(b) is a straight alkyl group having 6carbon atoms) and 1,1-(4,4′-dihydroxydiphenyl)decane (R_(a) is ahydrogen atom, and R_(b) is a straight alkyl group having 9 carbonatoms) are preferably used.

The polyhydroxy polyether resin represented by the formula (II) can besynthesized by a biphenol compound and a fluorenylidenediphenol compoundor their diglycidyl compounds.

In the above-mentioned formula (II), R⁹, R¹⁰, R¹¹ and R¹² are asmentioned above, may be the same or different from each other and eachrepresent a hydrogen atom, a straight or branched alkyl group having 1to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms or ahalogen atom. As the straight or branched alkyl group having 1 to 6carbon atoms, there may be mentioned, for example, a methyl group, anethyl group, an n-propyl group, an isopropyl group, an n-butyl group, anisobutyl group, a sec-butyl group, an n-pentyl group and an n-hexylgroup, etc., preferably a methyl group, an ethyl group, an n-propylgroup and an n-butyl group. As the hydroxyalkyl group having 1 to 6carbon atoms, there may be mentioned, for example, a hydroxymethylgroup, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutylgroup, a hydroxy-pentyl group and a hydroxyhexyl group, and preferably ahydroxymethyl group. As the halogen atom, there may be mentioned afluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.,and preferably a fluorine atom. Of these, a hydrogen atom, a methylgroup, a hydroxymethyl group and a fluorine atom are particularlypreferred. R_(c), R_(d), R_(e) and R_(f) are as mentioned above, may bethe same or different from each other and each represent a hydrogenatom, a straight or branched alkyl group having 1 to 6 carbon atoms, acycloalkyl group having 6 carbon atoms, an aryl group, an aralkyl groupor a halogen atom. As the straight or branched alkyl group having 1 to 6carbon atoms and the halogen atom, those as mentioned in the above R toR are mentioned. As the aryl group, there may be mentioned, for example,a phenyl group, a naphthyl group, an anthranyl group, etc., and thesegroups may have a substituent(s). As the aralkyl group, there may bementioned, for example, a benzyl group, a phenethyl group, etc., andthese groups may have a substituent(s). m is a number of a recurringunit and satisfying that a weight average molecular weight of thepolyhydroxy polyether resin in terms of standard polystyrene is 5,000 to1,000,000.

The biphenol compound to be used for synthesizing the polyhydroxypolyether resin represented by the above-mentioned formula (II) is thesame as mentioned in the formula (I) above except for the substituentsof R⁹ to R¹² as defined above.

As the fluorenylidenediphenol compound to be used for synthesizing thepolyhydroxy polyether resin represented by the above-mentioned formula(II), there may be mentioned, for example,4,4′-(9-fluorenylidene)-diphenol (R_(c), R_(d), R_(e) and R_(f) are allhydrogen atoms), 4,4′-(9H-fluoren-9-ylidene)bis[2-methylphenol] (R_(c)and R_(e) are alkyl groups having 1 carbon atom, and R_(d) and R_(f) arehydrogen atoms), 4,4′-(9H-fluoren-9-ylidene)bis[2,5-dimethylphenol](R_(c), R_(d), R_(e) and R_(f) are all alkyl groups having 1 carbonatom), 4,4′-(9H-fluoren-9-ylidene)bis[2,6-dimethylphenol] (R_(c), R_(d),R_(e) and R_(f) are all alkyl groups having 1 carbon atom),4,4′-(9H-fluoren-9-ylidene)bis[2-propenylphenol] (R_(c) and R_(e) arealkyl groups having 3 carbon atoms, and R_(d) and R_(f) are hydrogenatoms), 4,4′-(9H-fluoren-9-ylidene)bis[2-(1-methylethylphenol)] (R_(c)and R_(e) are alkyl groups having 3 carbon atoms, and R_(d) and R_(f)are hydrogen atoms),4,4′-(9H-fluoren-9-ylidene)bis[2-(2-methylpropyl)phenol] (R_(c) andR_(e) are alkyl groups having 4 carbon atoms, and R_(d) and R_(f) arehydrogen atoms),4,4′-(9H-fluoren-9-ylidene)bis[2-(1,1-dimethylethyl)phenol] (R_(c) andR_(e) are alkyl groups having 4 carbon atoms, and R_(d) and R_(f) arehydrogen atoms), 5,5′-(9H-fluoren-9-ylidene)bis(1,1′-biphenyl)-2-ol(R_(c) and R_(e) are hydrogen atoms, and R_(d) and R_(f) are benzylgroups), 4,4′-(9H-fluoren-9-ylidene)bis[2-cyclohexyl-5-methylphenol](R_(c) and R_(e) are alkyl groups having 1 carbon atom, and R_(d) andR_(f) are cycloalkyl groups having 6 carbon atoms) and4,4′-(9H-fluoren-9-ylidene)bis[2-fluorophenol] (R_(c) and R_(e) arefluorine atoms, and R_(d) and R_(f) are hydrogen atoms).

As the diglycidyl ether compounds, there may be mentioned compounds inwhich the above-mentioned biphenol compound, bisphenol compound orfluorenylidene compound is subjected to diglycidyl etherification.

The above-mentioned polyhydroxy polyether resin can be synthesized by asolution polymerization method. In the case of fusion and mixing, it isnot preferred since a high molecular weight resin cannot be prepared. Incase of the solution polymerization, it is carried out by, for example,(1) the biphenol compound and a diglycidyl ether compound of thebisphenol compound or the fluorenylidene diphenol compound, or (2) adiglycidyl ether compound of the biphenol compound and the bisphenolcompound or the fluorenylidene diphenol compound are dissolved in asolvent, which dissolves the polyhydroxy polyether resin which is anobjective material, such as N-methylpyrrolidone, etc., then, a base suchas sodium hydroxide, potassium carbonate, etc. is added to the solutionand the mixture is reacted at 100 to 130° C. for 1 to 5 hours tosynthesize a resin having a structure represented by the formula (I) or(II) which is a reaction product. As the polyhydroxy polyether resin tobe used as an adhesive of the present invention, preferred are thosehaving a weight average molecular weight (Mw) measured by gel permeationchromatography using tetrahydrofuran as a solvent of 5,000 or more to1,000,000 or less in terms of standard polystyrene. More preferred arethose having Mw of 10,000 or more to 450,000 or less. If it is less than5,000, the adhesive is likely to be brittle, while if it exceeds1,000,000, solubility of the resin lowers and preparation of an adhesivebecomes difficult. If it is less than 10,000, an adhesive has tackinessso that there is a fear of worsening workability at the time of peelingthe adhesive from a peelable substrate board. If it exceeds 450,000,fluidity of the adhesive is lowered and when connection between aconnecting terminal of an electronic member and a connecting terminal ofa circuit substrate is carried out, there is a fear of difficultlyfilling the adhesive between the electronic parts and the circuitsubstrate.

The polyhydroxy polyether resin represented by the formula (II) ispreferably an alternating copolymer of the biphenol derivative and thefluorenylidene diphenol derivative. If it is a block copolymer, it isdifficult to obtain a stable solubility, and a homopolymer of thefluorenylidene diphenol derivative is inferior in solubility while Tg iselevated. On the other hand, a biphenol polymer cannot give a high Tgpolymer while water absorption ratio is lowered.

As the aromatic hydrocarbon solvent, there may be mentioned, forexample, benzene, toluene, xylene and ethyl benzene. As the otherorganic solvent to be used by mixing with the aromatic hydrocarbonsolvent, an oxygen-containing organic solvent containing an oxygen atomin the molecule is preferred. As the oxygen-containing organic solvent,there may be mentioned, for example, an ester type solvent such as ethylacetate; a ketone type solvent such as acetone, methyl ethyl ketone,cyclohexanone, etc.; an ether type solvent such as tetrahydrofuran,dioxane, etc.; a solvent such as dimethyl sulfoxide, etc.; and an amidetype solvent such as dimethylformamide, N-methylpyrrolidone,N,N-dimethylacetamide, etc.

As (B) the three dimensionally cross-linkable resin to be used in theresin composition and the adhesive for the circuit substrate of thepresent invention, there may be mentioned an epoxy resin, a cyanateester resin, an imide type resin, an acrylate, methacrylate or maleimidecompound which are radical polymerizable substance, etc., and they areused in combination with a curing agent.

In the case of the epoxy resin, as a curing agent, a conventionallyknown imidazole type, hydrazide type, trifluoroborate-amine complex,sulfonium salt, amine imide, salt of polyamine, dicyane diamide, etc.may be used singly or in admixture of two or more. As the epoxy resin, abisphenol type epoxy resin derived from bisphenol A, F, S, AD, etc.; anepoxy novolak type resin derived from phenol novolak, cresol novolak,etc.; a naphthalene type epoxy resin having a naphthalene skeleton; aglycidyl amine type epoxy resin; a glycidyl ether type epoxy resin;various kinds of epoxy resin having two or more glycidyl ether groups inthe molecule such as biphenyl, alicyclic, etc., and other conventionallyknown epoxy resin singly or in admixture of two or more. As such anepoxy resin, a high purity product in which impurity ions such as analkali metal ion, an alkaline earth metal ion, a halogen ion,particularly a chlorine ion or hydrolyzable chlorine, etc. is reduced to300 ppm or less, is preferably used for the purpose of preventing fromelectromigration or corrosion of a circuit metal conductive material.

As the cyanate ester resin, there may be mentioned, for example,bis(4-cyanatophenyl)ethane, 2,2-bis(4-cyanatophenyl)propane,2,2-bis(3,5-dimethyl-4-cyanatophenyl)methane,2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane,α,α′-bis(4-cyanatophenyl)-m-diisopropylbenzene, a cyanate ester compoundof a phenol added dicyclopentadiene polymer, etc., and a prepolymerthereof is used singly or in admixture of two or more. Of these,2,2-bis(4-cyanatophenyl)propane,2,2-bis(3,5-dimethyl-4-cyanatophenyl)methane, etc. are preferred sincedielectric characteristics of the cured product are particularlyexcellent. As the curing agent for the cyanate ester resin, a metal typereaction catalyst is used. More specifically, there may be mentioned anorganic metal salt compound such as a 2-ethylhexanoate, a naphthenate,etc., and an organic metal complex such as an acetylacetone complex,etc.

An amount of the metal type reaction catalyst is preferably 1 to 3000ppm, more preferably 1 to 1000 ppm, further preferably 2 to 300 ppmbased on the amount of the cyanate ester compound. If the amount of themetal type reaction catalyst is less than 1 ppm, reactivity andcurabilitytend to be insufficient, while if it exceeds 3000 ppm, controlof the reaction becomes difficult or a curing takes place too fast, butthe amount is not specifically limited.

The acrylate, methacrylate and maleimide compound which are radicalpolymerizable substance are substances having a functional grouppolymerizable by a radical. The radical polymerizable substance can beused in either of the state of a monomer or an oligomer, and a monomerand an oligomer may be used in combination.

Specific examples of the acrylate (including a methacrylatecorresponding to the following acrylate, hereinafter the same) mayinclude, for example, methyl acrylate, ethyl acrylate, isopropylacrylate, isobutyl acrylate, ethylene glycol diacrylate, diethyleneglycol diacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, 2-hydroxy-1,3-diacryloxypropane,2,2-bis[4-(acryloxy-methoxy)phenyl]propane, dicyclopentenyl acrylate,tricyclodecanyl acrylate, tris(acryloyloxyethyl)isocyanurate, etc. Theseacrylates may be used singly or in admixture of two or more, and apolymerization inhibitor such as hydroquinone, methyl etherhydroquinone, etc., may be optionally used, if necessary. Also, when ithas a dicyclopentenyl group and/or a tricyclodecanyl group and/or atriazine ring, it is more preferred since heat resistance can beimproved.

As the maleimide compound, those having two or more maleimide group inthe molecule may be mentioned. As such a maleimide compound, there maybe mentioned, for example, 1-methyl-2,4-bismaleimidobenzene,N,N′-m-phenylenebismaleimide, N,N′-p-phenylenebismaleimide,N,N′-m-tolylenebismaleimide, N,N′-4,4-biphenylenebismaleimide,N,N′-4,4-(3,3′-dimethylbiphenylene)bismaleimide,N,N′-4,4-(3,3′-dimethyldiphenylmethane)bismaleimide,N,N′-4,4-(3,3′-diethyldiphenylmethane)bismaleimide,N,N′-4,4-diphenylmethanebismaleimide,N,N′-4,4-diphenylpropanebismaleimide, N,N′-4,4-diphenyl etherbismaleimide, N,N′-3,3′-diphenylsulfonebismaleimide,2,2-bis(4-(4-maleimidophenoxy)phenyl)propane,2,2-bis(3-s-butyl-4,8-(4-maleimidophenoxy)phenyl)propane,1,1-bis(4-(4-maleimidophenoxy)phenyl)decane,4,4′-cyclohexylidene-bis(1-(4-maleimidophenoxy)-2-cyclohexylbenzne,2,2-bis(4-(4-maleimidophenoxy)phenyl)hexafluoropropane, etc. These maybe used singly or in admixture of two or more.

As a curing agent for the radical polymerizable substance such as theacrylate, methacrylate and maleimide compound, etc., a curing agentwhich generates a free radical by heating or photoirradiation may beused. More specifically, it is preferably selected from an organicperoxide such as a peroxy ester, dialkyl peroxide, hydroperoxide, diacylperoxide, peroxydicarbonate, peroxyketal, silyl peroxide, etc., morepreferably, it is selected from a peroxy ester giving high reactivity.The above-mentioned curing agent may be optionally used in admixture oftwo or more.

As the peroxy ester, there may be mentioned, for example, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate,1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexylperoxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanonate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethylhexanonate,t-hexyl peroxy-2-ethylhexanonate, t-butyl peroxy-2-ethylhexanonate,t-butyl peroxyisobutyrate, 1,1-bis(t-butyl peroxy)cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butyl peroxy-3,5,5-trimethylhexanonate,t-butyl peroxylaurate, 2,5-dimethyl-2,5-di(m-toluoyl peroxy)hexane,t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexylmonocarbonate, t-butyl peroxybenzoate, t-butyl peroxyacetate, etc.

As the dialkyl peroxide, there may be mentioned, for example,a,a′-bis(t-butyl peroxy)diisopropylbenzene, dicumyl peroxide,2,5-dimethyl-2,5-di(t-butyl peroxy)-hexane, t-butylcumyl peroxide, etc.

As the hydroperoxide, there may be mentioned, for example,diisopropylbenzene hydroperoxide, cumene hydroperoxide, etc.

As the diacyl peroxide, there may be mentioned, for example, isobutylperoxide, 2,4-dichlorobenzoylperoxide, 3,5,5-trimethylhexanoyl peroxide,octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinicperoxide, benzoyl peroxytoluene, benzoyl peroxide, etc.

As the peroxydicarbonate, there may be mentioned, for example,di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate,bis(4-t-butylcyclohexyl) peroxydicarboante, di-2-ethoxymethoxyperoxydicarbonate, d-(2-ethylhexyl peroxy)dicarbonate, dimethoxybutylperoxydicarbonate, di(3-methyl-3-methoxybutyl peroxy)dicarbonate, etc.

As the peroxy ketal, there may be mentioned, for example,1,1-bis(t-hexyl peroxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butyl peroxy)-3,3,5-trimethylcyclohexane,1,1-(t-butyl peroxy)cyclododecane, 2,2-bis(t-butyl peroxy)decane, etc.

As the silyl peroxide, there may be mentioned, for example,t-butyltrimethylsilyl peroxide, bis(t-butyl)-dimethylsilyl peroxide,t-butyltrivinylsilyl peroxide, bis(t-butyl)divinylsilyl peroxide,tris(t-butyl)vinylsillyl peroxide, t-butyltriallylsilyl peroxide,bis(t-butyl)diallylsillyl peroxide, tris(t-butyl)allylsillyl peroxide,etc.

These curing agents which generate free radical can be used singly or inadmixture of two or more, and a decomposition promoting agent, aninhibitor, etc., may be mixed.

Also, when the above-mentioned curing agents are coated with a highmolecular weight substance such as a polyurethane type or a polyestertype polymer, etc., to form a microcapsule, it is preferred since ausable time of such a material can be elongated.

In the resin composition or the adhesive to be used for a circuit boardof the present invention, (A) the polyhydroxy polyether resin and (B)the three dimensionally cross-linkable resin are preferably formulatedin amounts (weight ratio, (A):(B)) of 1:99 to 99:1, more preferably10:90 to 90:10. If the amount of (A) the polyhydroxy polyether resin isless than 1 part by weight, low water absorption property, flexibilityand stress absorbing property possessed by the resin cannot be shown,while if it exceeds 99 parts by weight, the resulting material tends tohave lowered heat resistance.

To the resin composition or the adhesive to be used for a circuit boardof the present invention, a rubber component such as an acrylic rubberfor the purpose of lowering elasticity of the cured product may beadded.

Also, to the resin composition or the adhesive to be used for a circuitboard of the present invention, a thermoplastic resin such as a phenoxyresin, etc., may be added to make film formability easy. When an epoxytype resin is used as a base resin, the phenoxy resin is particularlysimilar in structure to the epoxy resin and has characteristicsexcellent in compatibility with the epoxy resin, excellent in adhesiveproperty, etc. so that it is preferred.

For forming a film from the resin composition or the adhesive to be usedfor a circuit board, it is carried out by dissolving or dispersing theresin composition or the adhesive containing the three dimensionallycross-linkable resin, its curing agent and the polyhydroxy polyetherresin in an organic solvent to prepare a varnish, coating the same on apeelable supporting material and removing the solvent at a temperaturelower than the active temperature of the curing agent. In particular, itis carried out by dissolving or dispersing the resin composition or theadhesive containing an epoxy resin as the three dimensionallycross-linkable resin, a latent type curing agent and the polyhydroxypolyether resin represented by the formula (I) and/or (II) in an organicsolvent to prepare a liquid material, coating the same on a peelablesupporting material and removing the solvent at a temperature lower thanthe active temperature of the curing agent.

As the solvent to be used at this time, the aromatic hydrocarbon typesolvent and the oxygen atom containing organic solvent as mentionedabove are preferred.

It is preferred that a coupling agent is formulated to the resincomposition or the adhesive of the present invention, and as thecoupling agent, a material having a vinyl group, an acryl group, amethacryl group, an amino group, an epoxy group or an isocyanate groupis preferred in the point of improving adhesiveness.

To the resin composition or the adhesive to be used for a circuit board,a conductive particle may be added for absorbing height fluctuation of abump of the chip or a substrate electrode, etc., to positively provideanisotropic conductivity.

As the conductive particle, there may be mentioned, for example metalparticles such as Au, Ni, Ag, Cu or a solder, etc., or metal particlesin which a thin film of gold or palladium, etc., is formed on the abovemetal particles by plating or deposition, etc. Also, conductiveparticles in which a conductive layer of Ni, Cu, Au or a solder, etc.,is formed on a spherical polymer core material such as a polystyrene,etc. may be used. The particle size is required to be less than theminimum distance of the electrodes of the substrate, and when there isfluctuation in a height of the electrodes, it is preferred to have alarger size than the height of fluctuation. When an inorganic filler isto be formulated, it is preferred to use the particles having largerthan the average particle size of the filler, more preferably 1 to 10μm. Also, an amount of the conductive particles to be dispersed in theadhesive is preferably 0.1 to 30% by volume, more preferably 0.2 to 20%by volume.

The resin composition or the adhesive to be used for a circuit board ofthe present invention can be easily prepared by dissolving or dispersingthe respective components in an organic solvent, and stirring and mixingby an optional method, and further by coating on a peelable supportingmaterial and removing the solvent at a temperature lower than the activetemperature of the curing agent to carry out formation of a film. Atthis time, in addition to the above-mentioned formulating compositions,any additive(s) to be used for preparing a usual epoxy resin compositionmay be added.

The thickness of the film state adhesive is not specifically limited,but it is preferably thicker than the gap between the first and thesecond circuit members, and generally desirable that it is thicker thanthe gap 5 μm or more.

EXAMPLES

In the following, the present invention is specifically explained byreferring to Examples.

Example 1

In 1000 ml of N-methylpyrrolidone were dissolved 45 g of1,1-(4,4′-dihydroxydiphenyl)undecane and 53 g of3,3′,5,5′-tetramethylbiphenol diglycidyl ether (epoxy equivalent: 194),and 23 g of potassium carbonate was added to the mixture and theresulting mixture was stirred at 110° C. After stirring for 3 hours, theresulting mixture was added dropwise to a large amount of methanol, anda formed precipitate was obtained by filtration to give 78 g of theresin (A) having a structure represented by the formula (I) as anobjective material. When a molecular weight of the resulting product wasmeasured by gel permeation chromatography (GPC 8020, trade name,manufactured by TOSO K. K., Japan) with columns of TSK gel G3000HXL andTSK gel G4000HXL both trade names, manufactured by TOSO K. K., Japanwith a flow rate of 1.0 ml/min, it was Mn=11112, Mw=17272 and Mw/Mn=1.55in terms of polystyrene standard.

The resin (A) having the structure represented by the formula (I) wasdissolved in THF (tetrahydrofuran), and the solution was coated to Petridish and the solvent was evaporated to form a cast film. The cast filmwas cut into 2 cm square, dried under reduced pressure at 100° C.,weighed and after dipping in pure water for 24 hours, weighed again tocalculate increase in weight so that a water absorption rate of thethermoplastic resin represented by the formula (I) was measured. As aresult of the water absorption ratio, the formed resin had a waterabsorption ratio of 0.7%. Also, a modulus of elasticity of the cast filmwas measured by using a dynamic viscoelasticity measurement device SolidAnalyzer RSA-II (trade name) manufactured by Rheometric Scientific Co.(a temperature raising rate: 5° C./min, 1 Hz), and Tg was measured bythe peak value of tan δ so that it was 72° C.

In 30 g of a mixed solvent of toluene:ethyl acetate=1:1 in a weightratio was dissolved 20 g of the formed polyhydroxy polyether resinrepresented by the formula (I) to obtain a 40% by weight solution. Then,to the above solution was added a 50% by weight solution comprising 4.3g of a trihydroxy ether type epoxy resin (epoxy equivalent: 195)dissolved in 8.6 g of a mixed solution of toluene: ethyl acetate=1:1 ina weight ratio, and then, to the resulting solution was added 28.6 g ofa commercially available liquid epoxy resin (a bisphenol F type epoxyresin, an imidazole type curing agent is encapsulated by the bisphenol Ftype epoxy resin, epoxy equivalent: 185) containing a microcapsule typelatent curing agent, and the mixture was stirred. Further, 3% by volumeof conductive particles prepared by providing a nickel layer with athickness of 0.2 μm on the surface of a polystyrene type core material(a diameter: 5 μm) and further forming an Au layer with a thickness of0.04 μm on the outside surface of the nickel layer was dispersed in theabove-mentioned solution to prepare a varnish solution for forming afilm. This solution was coated onto a separator (a polyethyleneterephthalate film treated by silicone, a thickness: 40 μm) as apeelable supporting material by using a roll coater, and dried at 70° C.for 10 minutes to prepare an adhesive film having a thickness of 30 μm.This adhesive film was cured at 180° C. for 20 seconds and further at150° C. for one hour. A modulus of elasticity of the resulting curedfilm was measured by using a dynamic viscoelasticity measurement device(a temperature raising rate: 5° C./min, 1 Hz), and Tg was measured bythe peak value of tan δ, which was 144° C.

Next, by using the thus prepared adhesive film, connection between agold bump (surface area: 80×80 μm, space: 30 μm, a height: 15 μm, anumber of bumps: 288)-attached chip (10×10 mm, a thickness: 0.5 mm) anda Ni/Au plated Cu circuit printed board (a height of electrode: 20 μm, athickness: 0.8 mm) was carried out as mentioned below. The adhesive film(12×12 mm) was tentatively connected to the Ni/Au plated Cu circuitprinted board at 60° C. and 0.5 MPa for 3 seconds, and then, theseparator was peeled off. After subjecting to positioning of the bump ofthe chip and the Ni/Au plated Cu circuit printing board, heating andpressurizing were carried out from the upper direction of the chip underthe conditions of 180° C., 100 g/bump for 20 seconds to carry out mainconnection to obtain a circuit board.

Connection resistance after main connection was 5 mΩ at the maximumvalue per bump, 1.5 mΩ with an average value and an insulationresistance was 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −55 to 125° C. was carriedout for 1000 cycles. Also, 200 hours of a PCT test (at 121° C., 2 atm)and 10 seconds dipping in a solder bath at 260° C. were carried out anda connection resistance was measured in the same manner as mentionedabove. As a result, there was no change in the values of 5 mΩ at themaximum value per bump and an insulation resistance of 10⁸ Ω or higher,so that good connection reliability was shown.

Example 2

The adhesive film attached with a separator obtained in Example 1 waspreserved at room temperature for one month, and then, a chip and asubstrate were connected in the same manner as in Example 1 to obtain acircuit board. A connection resistance of the circuit board afterconnection was 7.5 mΩ at the maximum value per bump, 1.7 mΩ with anaverage value and an insulation resistance was 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −55 to 125° C. was carriedout for 1000 cycles in the same manner as in Example 1. Also, 200 hoursof a PCT test (at 121° C., 2 atm) and 10 seconds of dipping in a solderbath at 260° C. were carried out and a connection resistance wasmeasured in the same manner as mentioned above. As a result, there wasno change in the values of 8 mΩ at the maximum value per bump, 1.9 mΩwith an average value and an insulation resistance of 10⁸ Ω or higher,so that good connection reliability was shown.

Example 3

In 30 g of a mixed solvent of toluene:ethyl acetate=1:1 in a weightratio was dissolved 20 g of the polyhydroxy polyether resin representedby the formula (I) prepared in Example 1 whereby a 40% by weightsolution was obtained. Then, to the above solution were added 20 g ofethylene glycol dimethacrylate and 2 g of benzoyl peroxide, and themixture was stirred. Further, 3% by volume of conductive particlesprepared by providing a nickel layer with a thickness of 0.2 μm on thesurface of a polystyrene type core material (a diameter: 5 μm) andfurther forming an Au layer with a thickness of 0.04 μm on the outsidesurface of the nickel layer was dispersed in the above-mentionedsolution to prepare a varnish solution for forming a film. This solutionwas coated onto a separator (a polyethylene terephthalate film treatedby silicone, a thickness: 40 μm) as a peelable supporting material byusing a roll coater, and dried at 70° C. for 10 minutes to prepare anadhesive film having a thickness of 30 μm. This adhesive film was curedat 180° C. for 20 seconds and further at 150° C. for one hour. A modulusof elasticity of the resulting cured film was measured by using adynamic viscoelasticity measurement device Solid Analyzer RSA-II (tradename) manufactured by Rheometric Scientific Co. (a temperature raisingrate: 5° C./min, 1 Hz), and Tg was measured by the peak value of tan δ,which was 96° C.

Next, by using the thus prepared adhesive film, connection between agold bump (surface area: 80×80 μm, space: 30 μm, a height: 15 μm, anumber of bumps: 288)-attached chip (10×10 mm, a thickness: 0.5 mm) anda Ni/Au plated Cu circuit printed board (a height of electrode: 20 μm, athickness: 0.8 mm) was carried out as mentioned below. The adhesive film(12×12 mm) was tentatively connected to the Ni/Au plated Cu circuitprinted board at 60° C. and 0.5 MPa for 3 seconds. After tentativeconnection, the separator was peeled off. After subjecting topositioning of the bump of the chip and the Ni/Au plated Cu circuitprinting board, heating and pressurizing were carried out from the upperdirection of the chip under the conditions of 180° C., 100 g/bump for 20seconds to carry out main connection to obtain a circuit board.

Connection resistance after main connection was 5 mΩ at the maximumvalue per bump, 1.5 mΩ with an average value and an insulationresistance was 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −55 to 125° C. was carriedout for 1000 cycles. Also, 200 hours of a PCT test (at 121° C., 2 atm)and 10 seconds of dipping in a solder bath at 260° C. were carried outand a connection resistance was measured in the same manner as mentionedabove. As a result, there was no change in the values of 5 mΩ at themaximum value per bump and an insulation resistance of 10⁸ Ω or higher,so that good connection reliability was shown.

Example 4

In 30 g of methyl ethyl ketone (MEK) was dissolved 20 g of thepolyhydroxy polyether resin represented by the formula (I) prepared inExample 1 whereby a 40% by weight solution was obtained. Then, to theabove solution were added 10 g of dicyclopentenyl acrylate, 3 g ofmethacryloxypropyl trimethoxysilane and 1 g of1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, and the mixture wasstirred. Further, 3% by volume of conductive particles prepared byproviding a nickel layer with a thickness of 0.2 μm on the surface of apolystyrene type core material (a diameter: 4 μm) and further forming anAu layer with a thickness of 0.04 μm on the outside surface of thenickel layer was dispersed in the above-mentioned solution to prepare avarnish solution for forming a film. This solution was coated onto aseparator (a polyethylene terephthalate film treated by silicone, athickness: 40 μm) as a peelable supporting material by using a rollcoater, and dried at 70° C. for 10 minutes to prepare an adhesive filmhaving a thickness of 30 μm. This adhesive film was cured at 180° C. for20 seconds and further at 150° C. for one hour. A modulus of elasticityof the resulting cured film was measured by using a dynamicviscoelasticity measurement device Solid Analyzer RSA-II (trade name)manufactured by Rheometric Scientific Co. (a temperature raising rate:5° C./min, 1 Hz), and Tg was measured by the peak value of tan δ, whichwas 120° C.

Next, by using the thus prepared adhesive film, tentative connectionbetween gold bumps (surface area: 50×50 μm and 50×90 μm, a number ofbumps: 178 and 184, respectively—attached chip (1.7×17.2 mm, athickness: 0.55 mm) and an ITO circuit glass substrate was carried outat 60° C. and 0.5 MPa for 3 seconds. After tentative connection, theseparator was peeled off. After subjecting to positioning of the bumpsof the chip and the ITO circuit glass substrate, heating andpressurizing were carried out from the upper direction of the chip underthe conditions of 200° C., 100 MPa/bump for 3 seconds to carry out mainconnection to obtain a circuit board.

Connection resistance after main connection was 100 mΩ at the maximumvalue per bump, 25 mΩ with an average value and an insulation resistancewas 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −40 to 100° C. was carriedout for 1000 cycles. Also, a high temperature and high humidity test at85° C./85% RH (relative humidity) was carried out for 1000 hours and aconnection resistance was measured in the same manner as mentionedabove. As a result, the connection resistance was 3.4 Ω at the maximumvalue per bump, 1.4 Ω with an average value and there was no change inthe value of an insulation resistance of 10⁸ Ω or higher, so that goodconnection reliability was shown.

Example 5

In 1000 ml of N-methylpyrrolidone were dissolved 45 g of4,4′-(9-fluorenylidene)-diphenol and 50 g of3,3′,5,5′-tetramethylbiphenol diglycidyl ether, and then, 21 g ofpotassium carbonate was added to the solution and the mixture wasstirred at 110° C. After stirring for 3 hours, the resulting mixture wasadded dropwise to a large amount of methanol, and a formed precipitatewas obtained by filtration to give 75 g of the resin (A) having astructure represented by the formula (II) as an objective material. Whena molecular weight of the resulting product was measured by gelpermeation chromatography (GPC 8020, trade name, manufactured by TOSO K.K., Japan) with columns of TSK gel G3000HXL and TSK gel G4000HXL bothtrade names, manufactured by TOSO K. K., Japan with a flow rate of 1.0ml/min, it was Mn=33471, Mw=143497 and Mw/Mn=4.29 in terms ofpolystyrene standard.

The polyhydroxy polyether resin (A) having the structure represented bythe formula (II) was dissolved in THF, and the solution was coated toPetri dish and the solvent was evaporated to form a cast film. A modulusof elasticity of the cast film was measured by using a dynamicviscoelasticity measurement device Solid Analyzer RSA-II (trade name)manufactured by Rheometric Scientific Co. (a temperature raising rate:5° C./min, 1 Hz), and Tg was measured by the peak value of tan δ, sothat a peak was observed at 95° C.

In 30 g of a mixed solvent of toluene:ethyl acetate=1:1 in a weightratio was dissolved 10 g of the formed polyhydroxy polyether resinrepresented by the formula (II) to obtain a 25% by weight solution.Then, to the above solution was added a 50% by weight solutioncomprising 4.3 g of a trihydroxy ether type epoxy resin (epoxyequivalent: 195) dissolved in 8.6 g of a mixed solution of toluene:ethyl acetate=1:1 (a weight ratio), and then, to the resulting solutionwas added 14.3 g of a liquid epoxy resin (a bisphenol F type epoxyresin, an imidazole type curing agent is encapsulated by the bisphenol Ftype epoxy resin, epoxy equivalent: 185) containing a commerciallyavailable microcapsule type latent curing agent, and the mixture wasstirred. Further, 3% by volume of conductive particles prepared byproviding a nickel layer with a thickness of 0.2 μm on the surface of apolystyrene type core material (a diameter: 5 μm) and further forming anAu layer with a thickness of 0.04 μm on the outside surface of thenickel layer was dispersed in the above-mentioned solution to prepare avarnish solution for forming a film. This solution was coated onto aseparator (a polyethylene terephthalate film treated by silicone, athickness: 40 μm) as a peelable supporting material by using a rollcoater, and dried at 100° C. for 10 minutes to prepare an adhesive filmhaving a thickness of 40 μm. This adhesive film was cured at 150° C. for3 hours. A modulus of elasticity of the resulting cured film wasmeasured by using a dynamic viscoelasticity measurement device (atemperature raising rate: 5° C./min, 1 Hz), and Tg was measured by thepeak value of tan δ, which was 182° C. Also, a preserved modulus ofelasticity at 40° C. was 2.1 GPa.

Next, by using the thus prepared adhesive film, connection between agold bump (surface area: 80×80 μm, space: 30 μm, a height: 15 μm, anumber of bumps: 288)-attached chip (10×10 mm, a thickness: 0.5 mm) anda Ni/Au plated Cu circuit printed board (a height of electrode: 20 μm, athickness: 0.8 mm) was carried out as mentioned below. The adhesive film(12×12 mm) was tentatively connected to the Ni/Au plated Cu circuitprinted board at 60° C. and 0.5 MPa for 3 seconds, and then, theseparator was peeled off after tentative connection. After subjecting topositioning of the bump of the chip and the Ni/Au plated Cu circuitprinting board, heating and pressurizing were carried out from the upperdirection of the chip under the conditions of 170° C., 30 g/bump for 20seconds to carry out main connection to obtain a circuit board.

Connection resistance after main connection was 5 mΩ at the maximumvalue per bump, 1.5 mΩ with an average value and an insulationresistance was 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −55 to 125° C. was carriedout for 1000 cycles. Also, 200 hours of a PCT test (at 121° C., 2 atm)and 10 seconds dipping in a solder bath at 260° C. were carried out anda connection resistance was measured in the same manner as mentionedabove. As a result, there was no change in the values of 5 mΩ at themaximum value per bump and an insulation resistance of 10⁸ Ω or higher,so that good connection reliability was shown.

Example 6

In 30 g of a mixed solvent of toluene:ethyl acetate=1:1 (weight ratio)was dissolved 20 g of the polyhydroxy polyether resin represented by theformula (II) prepared in Example 5 whereby a 40% by weight solution wasobtained. Then, to the above solution were added 20 g of ethylene glycoldimethacrylate and 2 g of benzoyl peroxide, and the mixture was stirred.Further, 3% by volume of conductive particles prepared by providing anickel layer with a thickness of 0.2 μm on the surface of a polystyrenetype core material (a diameter: 5 μm) and further forming an Au layerwith a thickness of 0.04 μm on the outside surface of the nickel layerwas dispersed in the above-mentioned solution to prepare a varnishsolution for forming a film. This solution was coated onto a separator(a polyethylene terephthalate film treated by silicone, a thickness: 40μm) as a peelable supporting material by using a roll coater, and driedat 70° C. for 10 minutes to prepare an adhesive film having a thicknessof 30 μm. This adhesive film was cured at 180° C. for 20 seconds andfurther at 150° C. for one hour. A modulus of elasticity of theresulting cured film was measured by using a dynamic viscoelasticitymeasurement device Solid Analyzer RSA-II (trade name) manufactured byRheometric Scientific Co. (a temperature raising rate: 50° C./min, 1Hz), and Tg was measured by the peak value of tan δ, which was 96° C.

Next, by using the thus prepared adhesive film, connection between agold bump (surface area: 80×80 μm, space: 30 μm, a height: 15 μm, anumber of bumps: 288)-attached chip (10×10 mm, a thickness: 0.5 mm) anda Ni/Au plated Cu circuit printed board (a height of electrode: 20 pm, athickness: 0.8 mm) was carried out as mentioned below. The adhesive film(12×12 mm) was tentatively connected to the Ni/Au plated Cu circuitprinted board at 60° C. and 0.5 MPa for 3 seconds. After tentativeconnection, the separator was peeled off. After subjecting topositioning of the bump of the chip and the Ni/Au plated Cu circuitprinting board, heating and pressurizing were carried out from the upperdirection of the chip under the conditions of 180° C., 100 g/bump for 20seconds to carry out main connection to obtain a circuit board.

Connection resistance after main connection was 5 mΩ at the maximumvalue per bump, 1.5 mΩ with an average value and an insulationresistance was 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −55 to 125° C. was carriedout for 1000 cycles. Also, 200 hours of a PCT test (at 121° C., 2 atm)and 10 seconds of dipping in a solder bath at 260° C. were carried outand a connection resistance was measured in the same manner as mentionedabove. As a result, there was no change in the values of 5 mΩ at themaximum value per bump and an insulation resistance of 10⁸ Ω or higher,so that good connection reliability was shown.

Example 7

In 30 g of MEK was dissolved 20 g of the polyhydroxy polyether resinrepresented by the formula (II) prepared in Example 5 whereby a 40% byweight solution was obtained. Then, to the above solution were added 10g of dicyclopentenyl acrylate, 3 g of methacryloxypropyltrimethoxysilane and 1 g of1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, and the mixture wasstirred. Further, 3% by volume of conductive particles prepared byproviding a nickel layer with a thickness of 0.2 μm on the surface of apolystyrene type core material (a diameter: 4 μm) and further forming anAu layer with a thickness of 0.04 μm on the outside surface of thenickel layer was dispersed in the above-mentioned solution to prepare avarnish solution for forming a film. This solution was coated onto aseparator (a polyethylene terephthalate film treated by silicone, athickness: 40 μm) as a peelable supporting material by using a rollcoater, and dried at 70° C. for 10 minutes to prepare an adhesive filmhaving a thickness of 30 μm. This adhesive film was cured at 180° C. for20 seconds and further at 150° C. for one hour. A modulus of elasticityof the resulting cured film was measured by using a dynamicviscoelasticity measurement device Solid Analyzer RSA-II (trade name)manufactured by Rheometric Scientific Co. (a temperature raising rate:5° C./min, 1 Hz), and Tg was measured by the peak value of tan δ, whichwas 150° C.

Next, by using the thus prepared adhesive film, tentative connectionbetween gold bumps (surface area: 50×50 μm and 50×90 μm, a number ofbumps: 178 and 184, respectively—attached chip (1.7×17.2 mm, athickness: 0.55 mm) and an ITO circuit glass substrate was carried outat 60° C. and 0.5 MPa for 3 seconds. After tentative connection, theseparator was peeled off. After subjecting to positioning of the bumpsof the chip and the ITO circuit glass substrate, heating andpressurizing were carried out from the upper direction of the chip underthe conditions of 200° C., 100 MPa/bump for 3 seconds to carry out mainconnection to obtain a circuit board.

Connection resistance after main connection was 100 mΩ at the maximumvalue per bump, 25 mΩ with an average value and an insulation resistancewas 10⁸ Ω or higher.

A number of these circuit boards were prepared in the same manner asmentioned above and a thermal shock test from −40 to 100° C. was carriedout for 1000 cycles. Also, a high temperature and high humidity test at85° C./85% RH (relative humidity) was carried out for 1000 hours and aconnection resistance was measured in the same manner as mentionedabove. As a result, the connection resistance was 3.4 Ω at the maximumvalue per bump, 1.4 Ω with an average value and there was no change inthe value of an insulation resistance of 10⁸ Ω or higher, so that goodconnection reliability was shown.

Comparative Example 1

In 30 g of a mixed solvent comprising toluene:ethyl acetate=1:1 in aweight ratio was dissolved 20 g of a phenoxy resin (Mn=20000, Mw=45000)to obtain a 40% by weight solution. Then, to the solution was added 28.6g of a liquid epoxy resin (a bisphenol F type epoxy resin, an imidazoletype curing agent is encapsulated by the bisphenol F type epoxy resin,epoxy equivalent: 185) containing a commercially available microcapsuletype latent curing agent, and the mixture was stirred. Further, 3% byvolume of conductive particles prepared by providing a nickel layer witha thickness of 0.2 μm on the surface of a polystyrene type core material(a diameter: 5 μm) and further forming an Au layer with a thickness of0.04 μm on the outside surface of the nickel layer was dispersed in theabove-mentioned solution to prepare a varnish solution for forming afilm. This solution was coated onto a separator (a polyethyleneterephthalate film treated by silicone, a thickness: 40 μm) as apeelable supporting material by using a roll coater, and dried at 70° C.for 10 minutes to prepare an adhesive film having a thickness of 30 μm.

Next, by using the thus prepared adhesive film, connection between agold bump (surface area: 80×80 μm, space: 30 μm, a height: 15 μm, anumber of bumps: 288)-attached chip (10×10 mm, a thickness: 0.5 mm) anda Ni/Au plated Cu circuit printed board (a height of electrode: 20 μm, athickness: 0.8 mm) was carried out as mentioned below. The adhesive film(12×12 mm) was tentatively connected to the Ni/Au plated Cu circuitprinted board at 60° C. and 0.5 MPa for 3 seconds, and then, theseparator was peeled off after tentative connection. After subjecting topositioning of the bump of the chip and the Ni/Au plated Cu circuitprinting board, heating and pressurizing were carried out from the upperdirection of the chip under the conditions of 180° C., 100 g/bump for 20seconds to carry out main connection to obtain a circuit board.

Connection resistance after main connection was 5 mΩ at the maximumvalue per bump, 1.5 mΩ with an average value and an insulationresistance was 10⁸ Ω or higher.

When the circuit board was treated by the PCT test (at 121° C., 2 atm)in the same manner as mentioned above, peeling was generated between thechip and the adhesive after 144 hours and connection failure occurred.

As compared with Comparative example 1, the circuit boards using thepolyhydroxy polyether resin represented by the formula (I) and/or (II)as the resin composition to be used in the present invention showedexcellent results in water absorption property and heat resistance asshown in the PCT test.

INDUSTRIAL APPLICABILIYT

The resin composition or the circuit board of the present inventioncontains the polyhydroxy polyether resin represented by the formula (I)and/or (II) as an adhesive, and its water absorption ratio is 0.1 to1.2% by weight and a glass transition temperature is 40 to 120° C. sothat they are excellent in humidity resistance and relaxation of stressof the adhesive agent whereby connection reliability can be improved.Also, by using a three dimensionally cross-linkable resin incombination, a cured product excellent in heat resistance can beobtained, and when it is used as a circuit board, connection reliabilitycan be markedly improved.

1. A resin composition which comprises (A) a polyhydroxy polyether resinrepresented by the following formula (I):

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ may be the same or differentfrom each other and each represent a hydrogen atom, a straight orbranched alkyl group having 1 to 4 carbon atoms, an alkenyl group having2 to 5 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms ora halogen atom; R_(a) represents a hydrogen atom or an alkyl grouphaving 1 to 2 carbon atoms; R_(b) represents a straight or branchedalkyl group having 2 to 13 carbon atoms; and n is a number of arecurring unit and satisfying that a weight average molecular weight ofthe polyhydroxy polyether resin in terms of standard polystyrene is5,000 to 1,000,000, and (B) a three dimensionally cross-linkable resin.2. The resin composition according to claim 1, wherein a waterabsorption ratio of the polyhydroxy polyether resin represented by theformula (I) is 0.1 to 1.2% by weight and a glass transition temperatureof the same is 40 to 100° C.
 3. The resin composition according to claim1, wherein a ratio of an amount of (A) the polyhydroxy polyether resinrepresented by the formula (I) and that of (B) the three dimensionallycross-linkable resin is (A)/(B)=1/99 to 99/1 in a weight ratio.
 4. Theresin composition according to claim 1, wherein (A) the polyhydroxypolyether resin represented by the formula (I) is dissolved in a mixedsolvent of an aromatic hydrocarbon organic solvent and anoxygen-containing organic solvent.
 5. The resin composition according toclaim 1, wherein (B) the three dimensionally cross-linkable resin is anepoxy resin and a latent curing agent is contained.
 6. The resincomposition according to claim 1, wherein (B) the three dimensionallycross-linkable resin is a radical polymerizable substance and a curingagent which generates a free radical by irradiation of light or heatingis contained.
 7. The resin composition according to claim 1, wherein thecomposition is obtained by dissolving (A) the polyhydroxy polyetherresin and (B) the three dimensionally cross-linkable resin in anaromatic hydrocarbon organic solvent and an oxygen-containing organicsolvent, uniformly mixing a solution, coating the solution and dryingand removing a coated material.
 8. The resin composition according toclaim 1, wherein the composition is obtained by curing the resincomposition containing (A) the polyhydroxy polyether resin and (B) thethree dimensionally cross-linkable resin by light or heat.
 9. The resincomposition according to claim 1, wherein the composition furthercomprises 0.1 to 20% by volume of conductive particles dispersedtherein.
 10. An adhesive for connecting a circuit member, whichinterposes between circuit electrodes opposed to each other, and, whenthese circuit electrodes opposed to each other are pressed, electricallyconnects these electrodes to a pressed direction, comprising (A) apolyhydroxy polyether resin represented by the following formula (I):

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ may be the same or differentfrom each other and each represent a hydrogen atom, a straight orbranched alkyl group having 1 to 4 carbon atoms, an alkenyl group having2 to 5 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms ora halogen atom; R_(a) represents a hydrogen atom or an alkyl grouphaving 1 to 2 carbon atoms; R_(b) represents a straight or branchedalkyl group having 2 to 13 carbon atoms; and n is a number of arecurring unit and satisfying that a weight average molecular weight ofthe polyhydroxy polyether resin in terms of standard polystyrene is5,000 to 1,000,000, and/or the following formula (II):

wherein R⁹, R¹⁰, R¹¹ and R¹² may be the same or different from eachother and each represent a hydrogen atom, a straight or branched alkylgroup having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6carbon atoms or a halogen atom; R_(c), R_(d), R_(e) and R_(f) may be thesame or different from each other and each represent a hydrogen atom, astraight or branched alkyl group having 1 to 6 carbon atoms, acycloalkyl group having 6 carbon atoms, an aryl group, an aralkyl groupor a halogen atom; and m is a number of a recurring unit and satisfyingthat a weight average molecular weight of the polyhydroxy polyetherresin in terms of standard polystyrene is 5,000 to 1,000,000, and (B) athree dimensionally cross-linkable resin.
 11. The adhesive forconnecting a circuit member according to claim 10, wherein a waterabsorption ratio of the polyhydroxy polyether resin represented by theformula (I) is 0.1 to 1.2% by weight and a glass transition temperatureof the same is 40 to 100° C.
 12. The adhesive for connecting a circuitmember according to claim 10, wherein a glass transition temperature ofthe polyhydroxy polyether resin represented by the formula (II) is 60 to120° C.
 13. The adhesive for connecting a circuit member according toclaim 10 wherein (A) the polyhydroxy polyether resin represented by theformula (I) and/or (II) is dissolved in a mixed solvent of an aromatichydrocarbon solvent and an oxygen-containing organic solvent.
 14. Theadhesive for connecting a circuit member according to claim 10, wherein(B) the three dimensionally cross-linkable resin is an epoxy resin andcontains a latent curing agent.
 15. The adhesive for connecting acircuit member according to claim 10, wherein the adhesive contains (A)the polyhydroxy polyether resin represented by the formula (I) and/or(II) capable of dissolving in a mixed solvent of an aromatic hydrocarbonsolvent and an oxygen-containing organic solvent, and an epoxy resin anda latent curing agent, or, a radical polymerizable substance and acuring agent which generates a free radical by irradiation of light orheating.
 16. The adhesive for connecting a circuit member according toclaim 10, wherein the adhesive is in a film state.
 17. The adhesive forconnecting a circuit member according to claim 10, wherein thecomposition further comprises 0.1 to 20% by volume of conductiveparticles dispersed therein.
 18. A circuit board which comprises a firstcircuit member having a first connecting terminal and a second circuitmember having a second connecting terminal which are so provided tooppose to each other, and an adhesive interposed between the firstconnecting terminal and the second connecting terminal opposed to eachother, and the first connecting terminal and the second connectingterminal opposed to each other being electrically connected by heatingand pressurizing, wherein said adhesive contains (A) the polyhydroxypolyether resin represented by the following formula (I):

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ may be the same or differentfrom each other and each represent a hydrogen atom, a straight orbranched alkyl group having 1 to 4 carbon atoms, an alkenyl group having2 to 5 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms ora halogen atom; R_(a) represents a hydrogen atom or an alkyl grouphaving 1 to 2 carbon atoms; R_(b) represents a straight or branchedalkyl group having 2 to 13 carbon atoms; and n is a number of arecurring unit and satisfying that a weight average molecular weight ofthe polyhydroxy polyether resin in terms of standard polystyrene is5,000 to 1,000,000, and/or the following formula (II):

wherein R⁹, R10, R¹¹ and R¹² may be the same or different from eachother and each represent a hydrogen atom, a straight or branched alkylgroup having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6carbon atoms or a halogen atom; R_(c), R_(d), R_(e) and R_(f) may be thesame or different from each other and each represent a hydrogen atom, astraight or branched alkyl group having 1 to 6 carbon atoms, acycloalkyl group having 6 carbon atoms, an aryl group, an aralkyl groupor a halogen atom; and m is a number of a recurring unit and satisfyingthat a weight average molecular weight of the polyhydroxy polyetherresin in terms of standard polystyrene is 5,000 to 1,000,000, and (B) athree dimensionally cross-linkable resin.
 19. The circuit boardaccording to claim 18, wherein (A) the polyhydroxy polyether resinrepresented by the formula (I) and/or (II) is dissolved in a mixedsolvent of an aromatic hydrocarbon solvent and an oxygen-containingorganic solvent.
 20. The circuit board according to claim 18, wherein awater absorption ratio of the polyhydroxy polyether resin represented bythe formula (I) is 0.1 to 1.2% by weight and a glass transitiontemperature of the same is 40 to 100° C.
 21. The circuit board accordingto claim 18, wherein a glass transition temperature of the polyhydroxypolyether resin represented by the formula (II) is 60 to 120° C.
 22. Thecircuit board according to claim 18, wherein (B) the three dimensionallycross-linkable resin is an epoxy resin and a latent curing agent iscontained.
 23. The circuit board according to claim 18, wherein theadhesive contains (A) the polyhydroxy polyether resin represented by theformula (I) and/or (II) capable of dissolving in a mixed solvent of anaromatic hydrocarbon organic solvent and an oxygen-containing organicsolvent, and an epoxy resin and a latent curing agent, or a radicalpolymerizable substance and a curing agent which generates a freeradical by irradiation of light or heating.
 24. The circuit boardaccording to claim 18, wherein the adhesive is in a film state.
 25. Thecircuit board according claim 18, wherein the composition furthercomprises 0.2 to 20% by volume of conductive particles dispersedtherein.